The present invention relates to a thin film magnetic head used for a magnetic recording apparatus such as a magnetic disc apparatus and a magnetic tape apparatus and, more particularly, to a thin film magnetic head including a plurality of insulating layers.
A thin film magnetic head has a tendency that the number of turns of a coil conductor is increased because writing on a recording medium such as a disc and a tape which confronts the head is performed through an intense magnetic field and a reproduction S/N (signal to noise ratio) characteristic is improved, and it also has a tendency that the number of insulating layers for insulating the coil conductor is accordingly increased.
A conventional thin film magnetic head is disclosed, for example, in Japanese Patent Unexamined publication No. 62-42311. In this example, the uppermost insulating layer is formed to have a pattern slightly larger than or substantially equal to a pattern of the lowermost insulating layer so as to form end portions of the insulating layers having a smooth face.
In another example disclosed in Japanese Patent Unexamined publication No. 58-62812, when forming insulating layers of a thin film magnetic head, photo-resist patterns are entirely exposed to light before, not after, they undergo a thermal treatment so as to obtain a smooth taper.
In a thin film magnetic head which includes insulating layers for insulating a coil conductor interposed therebetween, it has been difficult according to a conventional technique to accurately determine a position where the magnetic gap depth is zero, i.e., a position of the distal end of the selected insulating layer.
One object of the present invention is to provide a thin film magnetic head of an excellent electromagnetic conversion characteristic.